Apparatus and method for remote inspection of a structure using a special imaging system

ABSTRACT

The present invention relates to inspection of underground conduits, railroad bridge support structures and other facilities that may be examined remotely, using a video camera or other imaging system. The present invention provides fast and cost-effective systems and methods to inspect such structures remotely and to produce comprehensive and detailed information about inspected structures.

FIELD OF THE INVENTION

The present invention generally relates to the remote inspection ofareas that are difficult to reach. More specifically, the inventionrelates to inspection of underground conduits, railroad bridge supportstructures and other facilities that may be examined remotely, using avideo camera or other imaging system.

BACKGROUND OF THE INVENTION

It is sometimes necessary to inspect certain areas that are inconvenientand/or time-consuming to access. For illustrative purposes, theinspection of underground conduits will be described, although the scopeof the present invention is by no means limited to this application.Most municipalities contain a vast network of underground conduits.Periodically, these conduits must be inspected for problems such ascracks, blockage, build-up, and root infiltration. If a problem isdetected, detailed images must be obtained to facilitate planning toremedy the situation.

Conventional sewer inspection methods are globally the same as they weredecades ago. According to these conventional inspection methods, atarget pipe must be cleaned before a camera is winched through topinpoint problem areas. As a result, related inspection costs becometremendous due to costs of pumping and diverting water flow before theinspection (can double the costs of inspection of a small-diameter pipeand more than quintuple it in the case of larger sewer mains). Why wouldsewer pipes need to be cleaned for the sole purpose of being able towinch a camera through them? Experience has shown that, in over 70% ofcases, pipes do not need to be cleaned. In fact, mainly because ofbudgetary reasons, traditional methods are limited to inspect relativelysmall sections of sewer systems. Moreover, by flushing pipes out beforeinspection, vital information that could actually help to pinpoint theproblem could be destroyed. Such information comprises evidence ofleakage, deposits, root infiltration and inadequate water level.

On another side, imaging systems used for inspection of undergroundconduits should be specially accommodated to operate efficiently ingloomy, humid and difficult to reach areas in order to be able toprovide quality of imaging in a cost effective and a non time-consumingway. Traditional imaging systems for inspection of underground conduitslack efficiency because they are not suitably accommodated for suchinconvenient areas.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide apparatusand methods for remote inspection of a structure using a special imagingsystem that overcome the above drawbacks.

The present invention suggests fast and cost-effective systems andmethods to produce comprehensive and detailed assessments of givensections of sewer systems. The present new technique produces impeccabledetailed documentation to support budgetary requests and master plans.Therefore, it is possible to establish immediate inspection and cleaningpriorities while obtaining a “big-picture” view of what needs to be donein the long term.

According to one aspect of the invention, there is provided aninspection system comprising:

-   -   a mast;    -   a support member to support the mast;    -   a camera with a first interface unit to control attributes of        the camera, the camera being mounted on the mast;    -   a controllable high magnification ratio zoom with a zoom        controller to control the high magnification ratio zoom, the        zoom being mounted on the mast;    -   electronically controllable light projectors with a second        interface unit to control attributes of the light projectors,        the light projectors being mounted on the mast;    -   motors with a motor controller to mechanically control        orientation of the camera, the zoom and the light projectors        with respect to the mast; and    -   a third interface unit located in proximity of the camera, the        light projectors and the motors, the third interface unit having        a single input signal and output signals connecting the third        interface unit to each of the camera, the zoom controller, the        light projectors and the motor controller.

According to another aspect of the invention, there is provided aninspection system comprising:

-   -   a mast;    -   a support member to support the mast;    -   a camera having an output video signal, the camera being mounted        on the mast;    -   a server connected to the camera to store at least a part of the        video signal outputted by the camera; and    -   a workstation connected to the server to control the video        server to record the video signal and to transmit the recorded        video signal to the workstation.

According to another aspect of the invention, there is provided a methodof automatically generating attribute values defining controllableattribute values of an inspection imaging system, the method comprisingsteps of:

-   -   manually setting each of the attribute values to put the        inspection system in an initial state;    -   selecting a navigation template among stored navigation        templates, where the navigation template contains at least one        set of the attribute values defining controllable attribute        values of an inspection imaging system;    -   executing the navigation template during inspection of the        inspecting object to generate the at least one set of the        attribute values, the attribute values including camera        orientation, camera zoom and lighting intensity; and    -   sending the at least one set of the attribute values to the        inspection imaging system to automatically navigate according to        the selected navigation template.

According to another aspect of the invention, there is provided a systemfor automatically generating attribute values defining controllableattribute values of an inspection imaging system, the system comprising:

-   -   a user interface unit receiving user friendly data commands from        an end user to define the controllable attribute values;    -   a motor control module connected to the user interface unit to        acquire a first user friendly data command and outputting a        first attribute signal to control position and orientation of        the inspection imaging system;    -   a zoom module connected to the user interface unit to acquire a        second user friendly data command and outputting a second        attribute signal to control a high magnification ratio zoom of a        camera of the inspection imaging system;    -   a camera module connected to the user interface unit to acquire        a third user friendly data command and outputting a third        attribute signal to control attributes of the camera;    -   a light projector module connected to the user interface unit to        acquire a fourth user friendly data command and outputting a        fourth attribute signal to control attributes of electronically        controllable light projectors of the inspection imaging system;        and    -   an interface unit receiving the attribute signals and outputting        corresponding imaging system control signals;    -   a storage unit storing navigation templates, where each of the        navigation templates contains at least one set of the attribute        values defining the controllable attribute values of the        inspection imaging system;    -   a select module connected to the storage unit to select a        navigation template among the navigation templates in the        storage unit; and    -   an execute module connected to the select module to execute the        desired navigation template and to output the desired navigation        template to the imaging system via the interface unit.;

According to further aspect of the invention, there is provided a methodof creating an identification header using a database to automaticallyextract information in connection with an inspecting object, the methodcomprising steps of:

-   -   navigating an inspection imaging system mounted on a mast        supported by a support member to inspect the inspecting object;    -   recording the inspection to create an inspection video in        connection with the inspecting object;    -   selecting the inspecting object in a database containing        information about the inspecting object;    -   extracting, from the database, the information about the        inspecting object;    -   using the extracted information for automatically editing a text        identification header in connection with the inspecting object;        and    -   merging the text identification header with the inspection video        in connection with the inspection object.

According to further aspect of the invention, there is provided a systemfor creating an identification header using a database to automaticallyextract information in connection with an inspecting object, the systemcomprising:

An inspection imaging system mounted on a mast supported by a supportmember to inspect the inspecting object;

-   -   a storage unit containing information about a given group of        inspecting objects;    -   a select module connected to the storage unit to select the        inspecting object among the given group of inspecting objects in        the storage unit;    -   a header edit module connected to the select module to edit an        identification header in connection with the inspecting object;        and    -   a video merge module connected to the header edit module to        merge the edited identification header with an inspection video        in connection with the inspecting object.

According to further aspect of the invention, there is provided aninspection imaging system mounted on a mast supported by a supportmember, the imaging system comprising:

-   -   a camera with an electronically controllable high magnification        ratio zoom to perform inspections both from close up and from a        distance;    -   at least five light projectors to provide necessary lighting in        the underground conduit; and    -   a housing containing the camera and the light projectors, the        camera being centered in the housing and the light projectors        surrounding the camera.

According to further aspect of the invention, there is provided a methodof inspecting an inspection object, the method comprising steps of:

-   -   determining appropriate optical composition of light to project        as a function of an imaging environment;    -   selecting appropriate optical filters as a function of the        appropriate optical composition of light to project;    -   placing the selected optical filters in front of light        projectors of the inspection system, such that light projected        by the light projectors on the inspection object is filtered by        effect of the placed optical filters;    -   acquiring an image of the inspection object; and    -   analyzing the acquired image as a function of the optical        composition of the projected light.

In the inspection system comprising light projectors, it is preferablethat it comprises a power supply converter located in proximity of thelight projectors, the power supply converter receiving a 48 voltscurrent via a 48 volts cable connected to a remote power supply unit andconverting the 48 volts to a 12 volts current in order to supply thelight projectors.

In the inspection system comprising a camera with an output video signalconnected to a server, the camera can be an analog camera having acontrollable zoom, controllable orientation and controllable lightingfor illuminating and imaging the conduit. In this case, the output videosignal is an output analog video signal. The server can be part of afield relay unit providing power to the camera, the lighting andpositioning motors, the field relay unit being connected to the camerato provide control signals and receive the output analog video signalfrom the camera and to the workstation via a data bus. It is preferablethat the server comprises:

-   -   a CODEC device receiving the output analog video signal and        converting the output analog video signal into a digital video        signal and compressing the digital video signal for storage; and    -   a monitor image generator for sending a live monitor image from        the camera to the workstation over the data bus.

The inspection systems of the present invention preferably comprisemotors mounted on the mast to mechanically control orientation of thecamera with respect to the mast.

In the method of automatically generating attribute values, it ispreferable that the at least one set of the attribute values comprises asequence in time of a group of sets of the attribute values. Inaddition, the navigation template can represent a marked state ofattributes and the step of sending the at least one set of attributevalues can comprise sending one set of attribute values defined by themarked state. Besides, the step of selecting a navigation templatepreferably comprises selecting the navigation template as a function ofa type of the inspecting object.

The system for automatically generating attribute values preferablycomprises a state save module connected to the storage unit for storing,as a navigation template, the attribute signals corresponding to acurrent state.

In the imaging system, the housing has preferably a common faceplate forboth the camera and the light projectors. The housing has preferably ahexagonal shape and preferably comprises cooling fins and at least onethermoelectric cooling device to dissipate heat generated by the lightprojectors. In addition, the housing preferably comprises apertures ofstandard dimensions that can receive standard 58 millimeter lens filtersand inside of which the light projectors are located, such that lightprojected by the light projectors is filtered by effect of the standardlens filters. Besides, the imaging system preferably comprises a mast tosupport components of the imaging system and motors to mechanicallycontrol orientation of the imaging system with respect to the mast.

In the method of inspecting an inspection object using optical filters,the imaging environment can be a wall of an underground conduit and, inthis case, the selection of appropriate optical filters is carried outas a function of at least one of humidity inside the underground conduitand material of the wall such that the acquired image shows defects ofthe wall. The imaging environment can also be an underground conduitfilled with liquid and, in this case, the selection of appropriateoptical filters is carried out as a function of at least one of humidityinside the underground conduit and reflection properties of the liquidsuch that said acquired image shows the underground conduit withoutlight projected by the liquid.

BRIEF DESCRIPTION OF DRAWINGS

These and other features of the present invention will become moreapparent from the following description in which reference is made tothe appended drawings wherein:

FIG. 1 is a block diagram of an imaging system according to a preferredembodiment of the invention;

FIG. 2 is a block diagram of an imaging system according to anotherpreferred embodiment of the invention;

FIG. 3 is a flow chart of a method of marking a state of controllableattributes of components of an imaging system according to a preferredembodiment of the invention;

FIG. 4 is a block diagram of a system for marking a state ofcontrollable attributes of components of an imaging system and using themarking state to edit and use a navigation template according to apreferred embodiment of the invention;

FIG. 5 is a flow chart of a method of inspection of an undergroundconduit using a navigation template according to a preferred embodimentof the invention;

FIG. 6 is a flow chart of a method of creating an identification headerusing a database to automatically extract information in connection withan inspected underground conduit according to a preferred embodiment ofthe invention;

FIG. 7 is a block diagram of a system for creating an identificationheader using a database to automatically extract information inconnection with an inspected underground conduit according to apreferred embodiment of the invention;

FIG. 8 is a flow chart of a method of inspecting an inspection objectusing optical filters.

DESCRIPTION OF PREFERRED EMBODIMENTS

The imaging system used in the present invention is not a regularimaging system that can be hold over a shoulder but is a special imagingsystem mounted on a mast supported by a support member that is usuallyfixed to an inspection truck. For illustrative purposes, the inspectionof underground conduits will be described, although the scope of thepresent invention in by no means limited to this application. In fact,the invention relates to the remote inspection of structures that may beexamined remotely using an imaging system, such as underground conduitsand railroad bridge support structures.

In the text, when it is referred to “imaging system”, it should beunderstood that it is referred to the part of the inspection system thatis placed inside the inspecting underground conduit for imaging. The“imaging system” does not include components that do not constitute apart of the system placed inside the conduit for inspection. However,when it is referred to “inspection system”, it should be understood thatit is referred to the whole system used for inspection. This comprisesthe imaging system as well as other components used directly orindirectly in connection with the “imaging system”.

Referring first to FIG. 1, there is shown an imaging system forinspection of an underground conduit 46 connected to a workstation 10 bythe intermediary of a field relay 16 with a harness 27 located in thefield in proximity of the workstation 10 and far from the imaging system46. The imaging system 46 comprises a camera 30 with controllableattributes, a high magnification ratio zoom with a zoom controller 32, amotor with a motor controller 36 and light projectors 34. The camera 30can be either a digital or an analog one, but the zoom is necessarily anoptical one to be able to provide the required quality of image. It isalways possible to have simultaneously a digital and an optical zoom.The light projectors 34 are preferably electronically controllable lightprojectors to be able to vary their intensity.

Preferably, the imaging system 46 comprises an interface unit 28 locatedin proximity of the camera 30, the zoom, the light projectors 34 and themotors. The harness 27 comprises a video cable 22 connected to thecamera 30, an attribute cable 24 connected to the interface unit 28 anda power cable 26 connected to each of the camera 30, the lightprojectors 34 and the motor controller 36 of the imaging system 46.

Preferably, the imaging system 46 is controlled manually from theworkstation 10 from which an operator sends a control signal via a USBconnection 12 to control the camera 30, the camera zoom, the lightprojectors 34 and the motors. Following, the field relay 16 receives thecontrol signal sent by the workstation 10 and, in consequence, transmitsvarious attribute signals over a single attribute cable 24 to controlthe different components of the imaging system 46. The attribute signalsinclude attribute values of the camera 30, attribute values of the zoom,attribute values of the light projectors 34 and attribute values of themotors.

The imaging system 46 is electrically supplied by the means of a powersupply preferably located in the field relay 16. Accordingly, the fieldrelay 16 comprises a 110 volts socket connected to each of the camera30, the light projectors 36 and the motor controller 36 by a power cable26. The same power cable 26 is also connected to supply the display 20located in proximity of the field relay 16.

The field relay 16 comprises a video input for receiving, via a firstvideo cable 22, a video signal recorded by the camera 30. It is possiblefor the field relay 16 to be connected to the workstation 10 by a secondvideo cable 14 to convey the received video signal for storage in theworkstation 10. When the received video signal is an analog signal, aCODEC device located in the worsation 10 receives the analog videosignal, converts it into a digital video signal and then compresses thedigital video signal for storage.

Even if it is possible to store the video signal in the workstation 10,it is preferable to have an independent server for this purpose.Accordingly, FIG. 2 shows a video server 50 connected to the field relay16 by a fourth video cable 48. When the received video signal is analog,the video server 50 comprises a CODEC device to receive,.convert andcompress the received signal.

The importance to have a video server 50 independent of the workstation10 is ordered by the fact that the vast majority of the existing trucksused for video inspections are either equipped with workstations havinganalogical mode equipments, such as a VHS video tape recorder, or withworkstations having inappropriate characteristics for video imagestorage. The digitalization of video signals in real time requires acomputer with a very specific architecture and data-processingcomponents especially dedicated for this purpose.

It is preferable, in order to ensure fluidity of the image duringviewings and recordings, that the server comprises several componentswith special characteristics, such as a video card with a video entry ofa very good quality and a hard disk system of type Raid with a minimumspeed of 7200 spins/s to store the video data. Furthermore, it ispreferable to have a minimum of 512 MB of read-write memory and amotherboard equipped with at least a Pentium IV processor. A server withsuch characteristics is required to provide a good quality of image. Itis also possible, after installation of especially dedicated software,to be connected to the server via a local or a remote connection (ex.USB, WIFI and Internet) in order to control recording and transferringof the video signal.

According to a preferred embodiment of the invention, the field relay 16comprises a TV output from which the received video signal is conveyedto a display 20 via a third video cable 18. The display 20 can be ananalog or a digital one according to if the received video signal isanalog or digital. The display 20 is located in the field and displaysthe video signal recorded by the camera 30. The first utility ofdisplaying the video signal is that it allows the operator to visualize,in real time, the video signal recorded by the camera 30, giving him thepossibility to further control in consequence the attributes of thecomponents of the imaging system 46 (i.e. zoom, light intensity,orientation of the camera, brightness of the image, etc.). Anotherutility of displaying the video signal is to allow an assistant operatorin the field to position the imaging system appropriately in the middleof the inspecting underground conduit, the operator assistant beingguided by the video image displayed. Without this innovation, it ispractically impossible to carry out this operation efficiently due tothe deepness of underground conduits. Another utility is that heoperator can also control which part of the recorded video signal tostore.

The interface unit 28 of the imaging system 46 is responsible of all theintelligence of the imaging system 46. Even if it can also be located inthe field relay 16, the interface unit 28 is preferably located in theimaging system 46. The interface unit 28 is provided with amicrocontroller preferably containing special software using thestandard protocol of communication MODBUS that allows receiving andconverting signals (i.e. VISCA or other types of signals) via a singleinput interface and corresponding each of these received signal to itsappropriate output interface, among a group of output interfaces. In theevent, the interface unit 28 receives the attribute signals over theattribute cable 24 and conveys the received attribute signals to theirrespective output interfaces so that they can be forwarded toward theirrespective destinations (i.e. camera 30, zoom, light projectors 34 andmotors) by the means of various cables. Accordingly, the interface unit28 transmits the camera attribute values to the camera 30 via a firstattribute cable 38, the zoom attribute values to the zoom controller 32via a second attribute cable 40, the light attribute values to the lightprojectors 34 via a third attribute cable 42 and the motor attributevalues to the motor controller 36 via a fourth attribute cable 44.

In this approach, one of the advantages to locate the interface unit 28in the imaging system 46 (and not in the field relay 16) is to decreasethe size of the harness 27 between the field relay 16 and the imagingsystem 46, making it more flexible and easy to work.

The light projectors 34 are preferably electronically controllable lightprojectors comprising a group of projectors surrounding the camera 30.The projectors can be either bulbs or leds. Given the big number ofprojectors and in order to further decrease the size of the harness 27,it is preferable to supply the light projectors 34 from a power supplysource with a converter located in their proximity. With this intention,instead of supplying the light projectors 34 from the field relay 16with 12 volts current, it is possible to supply it with 48 volts current(that requires a thinner cable) and to convert it to 12 volts currentwith a 48 to 12 volts converter located in the imaging system 46.

In the course of inspection, many reasons justify the need to memorize,at a given instant, the state of attributes of the components of theimaging system. Considering the loss of time and the lack of accuracy inadjusting manually the attributes, the system allows memorizing a stateof attributes at any instant during inspection, doesn't matter if thesystem is in an automatic or a manual mode, changing the state ofattributes and then setting up the system automatically according to thememorized state of attributes. To do so, the motors are equipped withspecial sensors capable of detecting orientation and position of theimaging system in space. Thereafter, the system memorizes the detectedorientation and position of the imaging system. From their side, theattributes of the light projectors, of the zoom and of the camera arecontinuously monitored, such that when the mark state command istriggered, the system reads and memorizes the last state of attributesof the components of the imaging system.

For instance, one among the utilities of marking a state is when theimaging system is in an automatic mode and the operator wants totemporally interrupt the automatic mode (for instance, to inspectmanually a given zone in the field of view of the camera) and then goesback to it without loosing the state of attributes of the componentsright before the interruption. By marking the state of the attributesbefore interrupting the automatic mode of the imaging system, theoperator will be able to put the system in a manual mode, change thestate of the attributes according to the needs (ex. change the zoom, theintensity of the projectors, the orientation of the camera, etc.) andthen set up the system with the same state of attributes as right beforethe interruption.

Referring to FIG. 3, there is shown a method of marking a state ofcontrollable attributes of components of an imaging system. Initially,at least a part of the attributes of the system are put in a first state(70, 78 and 86). Following, at least a part of the attributes put in thefirst state are selected and have their state memorized and stored in astate marker 94 (72, 80 and 88). The attributes values of the componentsare then changed and put in a second state (74, 82 and 90). Finally, thesystem selects the marked state and instates the memorized state of theselected attributes (76, 84 and 92).

Referring to FIG. 4, there is shown a system for marking a state ofcontrollable attributes of components of an imaging system. The systemfor marking a state of attributes is generally located in theworkstation 10 and comprises a navigation motor controller 110, a zoommodule 114, a camera setting module 118, a lighting controller 122, abus interface unit 126, a state saver 128, a state marker 130, a stateselector/executer 132. The workstation 10 (that generally comprises thesystem for marking a state of attributes) is connected to the imagingsystem 46 via the field relay 18.

The navigation motor controller 110 is a module that receives a motorcontrol signal for controlling the motor and sends a motor attributesignal 112 containing motor attribute values to the bus interface unit126. The motor control signal is generated by an appropriateuser-friendly interface, such as a joystick, manipulated by theoperator. The zoom module 114 is a module that receives a zoom controlsignal generated by the operator for controlling the zoom of the cameraand sends a zoom attribute signal 116 containing zoom attribute valuesto the bus interface unit 126. Similarly, the camera setting module 118receives a camera control signal generated by the operator forcontrolling the camera and sends a camera attribute signal 120containing camera attribute values to the bus interface unit 126.Finally, the lighting controller 122 is a module that receives a lightcontrol signal generated by the operator for controlling the lightprojectors and sends a light attribute signal 124 containing lightprojectors attribute values to the bus interface unit 126. All of thenavigation motor controller 110, the zoom module 114, the camera settingmodule 118 and the lighting controller 122 are preferably softwaremodules.

The bus interface unit 126 conveys the received attribute signals (112,116, 120 and 124) to the imaging system 46 via the field relay 18 inorder to control the different components of the imaging system. Theoperator at the workstation 10 supervises, by the means of the display20, the change of state of the attributes of the different components.If the operator decides to mark the state of the attributes, the businterface 126 conveys the attribute signals to the state saver 128 tosave the attribute values. Thereafter, the state saver 128 sends theseattribute values for storage in the state marker 130. In the course ofinspection, when the operator selects the marked state for execution,the state selector/executer 132 sends an attribute signal 144 with thememorized state of attributes to the bus interface 126 to be thereafterconveyed to the imaging system 46 to control the different components.

The number of types of materials used to construct underground sewersexceeds 25 different types (ex. sandstone, steel, PVC) and they arelisted and used in all the countries of the world. In general, allsewage networks are built according to a same general principleaccording to which conduits of small diameters are located upstream ofthe basin of drainage and conduits of bigger diameters are locateddownstream, towards the more significant collectors. The diameters thusvary from 4 inches to more than 12 feet. A typical sewage networkconsists of a score of different diameters. Each material has acharacteristic color (ex. white, black, blue, red, etc).

Since its beginnings in the middle of the Fifties, the industry ofsewers inspection encounters a persistent difficulty to generate a filmaccurately reproducing the real conditions observed in the conduits.Several factors combine to make the spot difficult. One among otherfactors is that the type of the inspected conduit (i.e. mainly, thediameter of the conduit and it's type of material) influences on thereflection of the projected light and therefore impacts the quality ofthe recorded image. Consequently, in order to ensure a quality of imageof the inspecting conduit, the attributes of the imaging system (ex. theiris, the gain, the contrast, the shutter speed, the back lightcompensation, etc.) should be adjusted as a function of the type of theinspecting conduit.

There is a big range of conduit types used in industry (i.e.approximately 500:25 different material types×20 different diameterdimensions). Adjusting manually attributes of the camera as a functionof each conduit type encountered during inspection is therefore a hugetime consuming and is practically impossible.

The norms of inspection being clearly defined by the municipalauthorities, the actions constituting a standard inspection are clearlydetailed and known. In this view, a standard inspection of anunderground conduit is generally constituted of a series of repetitiveactions, where each action is generally constituted of three phases: 1)positioning the camera in the center of the conduit and carrying out arotating movement from 7 to 6 hours in order to inspect the crown of thepipe, 2) making a zoom-in and 3) making a zoom-out). The rotation angleof the camera and the intensity of the light projectors must be selectedappropriately according to a type of the inspecting conduit (i.e.diameter dimensions and type of material).

The conduit inspection standardization makes it possible to automateconduit inspection systems. In this order, the system uses navigationtemplates especially adapted for various types of inspecting conduits.Each navigation template contains, for a given type of an inspectingconduit, at least one set of predefined attribute values of thecomponents of the imaging system (i.e. attributes of the camera,attributes of the projectors, attributes of the motors, attributes ofthe zoom, etc). Navigation templates can have one set of attributevalues but, generally, they contain a sequence in time of a group ofsets of attribute values allowing the inspection system to operate in anautomated mode for a given period of time. Also, navigation templatescan, partially or totally, be made of one or a group of marked states.

Generally, a navigation template operates as follows: once the imagingsystem positioned in the center of the pipe, the operator selects theinspecting conduit type (i.e. the diameter and the type of material) andthe system automatically selects and executes a suitable navigationtemplate as a function of the selected inspecting conduit. Thereafter,all the attributes of the components of the imaging system are adjustedautomatically. If the given navigation template contains a sequence intime of a group of attribute values, the imaging system will thennavigate in an automated mode for a given period of time. The operatorvisualizes the course of the operation by the means of the display 20 orthe workstation 10.

It is possible to conceive a navigation template that, when executed,activates attributes of only a part of components of an imaging system.This makes it possible to automate only a part of the components of theimaging system (for instance, automating the zoom) and to preserve amanual mode for the other part of the components (for instance,preserving a manual operability to vary the intensity of the projectorsand the orientation of the camera). A navigation template can also beinterrupted in court of execution while preserving a marker (statemarker) memorizing the attribute values of the components of the imagingsystem right before the interruption. The system also allows thecreation of new navigation templates for new types of conduits notenvisaged originally by the system.

Thanks to navigation templates, the inspection of conduits becomes muchless time consuming because the need for repetitive manual adjustmentsis minimized. The productivity is therefore increased.

Referring to FIG. 5, there is shown a method of inspection of anunderground conduit using a navigation template. Generally, navigationtemplates are edited 180 and stored 182 in a navigation template server190 before starting the inspection. Even if navigation templates areusually edited as a function of types of inspecting conduits and storedprior to the inspection, it is always possible to edit navigationtemplates in the course of inspection, for instance, by marking andmemorizing a given state of attributes. Following the edition 180 andthe storage 182 steps, the operator selects a given navigation template(among a group of navigation templates) 184 from the navigation templateserver (that can be the same physical device as the workstation) 190 tobe eventually executed 186. Generally, the selection of the navigationtemplate is carried out as a function of the type of the inspectingconduit. Upon execution of the selected navigation template, theattribute values contained in the selected navigation template are sentto the imaging system to automatically navigate the imaging systemaccording the selected navigation template 188. In other words, thesystem changes the previous state of attributes of the components of theimaging system to a new one according to content of the executednavigation template 188.

Referring to FIG. 4, there is shown a system for inspecting anunderground conduit using a navigation template. The system comprises anavigation template editor 134, a navigation template server 136, anavigation template selector 138 and a navigation template executer 140.Normally, all these components are located within the workstation 10.The navigation template editor 134 allows editing new navigationtemplates and is connected to the navigation template server 136 tostore the edited navigation templates. According to one aspect of theinvention, the navigation template editor 134 is also connected to thestate maker 130 to receive a marked state when required. In fact, theedited navigation templates are usually edited manually and stored priorto the inspection, but it is also possible to edit navigation templatesfrom the marked states of attributes. The navigation template selector138 allows selecting a given navigation template according to a choiceof the operator and it is connected to the navigation template server136 to select and receive the given navigation template among a group ofstored navigation templates. The navigation template executer 140 isresponsible for executing the selected navigation template and sendingthis selected navigation template to the imaging system 46. Therefore,the navigation template executer 140 is connected to the navigationtemplate selector 138 to receive and execute the selected navigationtemplate. The navigation template executer 140 is also connected to thebus interface unit 126 to send to the imaging system an attribute signal144 containing the selected navigation template 46 for automaticallynavigating the imaging system 46 according to the selected navigationtemplate.

After inspection, the video generated in connection with a giveninspected conduit should be clearly identified. To be able to associatecorrectly an inspection video file with its corresponding inspectedunderground conduit, the video file is labeled as a function of thenames of the conduit and of the inspection project. Also, the systemallows inserting, at the beginning of the introduction video, anintroduction video containing identification information about theinspected: conduit to clearly identify the latter. Identificationinformation comprises the number, the geographic localization and thetype (i.e. material type and dimensions) of the conduit.

Entering the identification information manually is subject to humanerrors, where the need to enter the information automatically, withouthuman intervention. Referring to FIG. 6, there is shown a method ofcreating an identification header using a database to automaticallyextract information in connection with an inspected underground conduit.The operator starts by selecting, from a database 198 (i.e. geographicalor relational database), the inspected underground conduit 190.Thereafter, the system extracts, from the database 198, information inconnection with the inspected underground conduit 192. Such informationcomprises the number, the localization and the type of the inspectedunderground conduit. Following, the system automatically edits a textidentification header in connection with the inspected undergroundconduit 194 and stores the text header in a text header server 200.Finally, the system merges the edited identification header with theinspection video in connection with the inspected underground conduit196. This method being free of any human intervention, editing errors(that usually occur when information is entered manually) areeliminated. Moreover, this automated method is faster and more reliablethan any other manual method used for creating identification headers inconnection with conduits. When the edited information header containstoo much information to fit within a sole page, the system spreadsautomatically the identification information over as many consecutivepages as necessary.

Referring to FIG. 7, there is shown a system for creating anidentification header using a database to automatically extractinformation in connection with an inspected underground conduit. Thesystem comprises a database 198 (i.e. geographical or relationaldatabase), an underground conduit selector 210, a header editor 212, atext header server 200, a video merger 214 and an interface unit 216.The underground conduit selector 210 is connected to the database 198 toselect the inspected conduit among a group of conduits and to extractinformation in connection with the selected underground conduit. TheHeader editor 212 is connected to the underground conduit selector 210to receive information about the selected underground conduit.Thereafter, the header editor proceeds to edit an identification headeraccording to the received information and stores the editedidentification header in the text header server 200. When activating theheader edition process, the operator can choose editing options, such ascharacters' style, size and color. The video merger 214 is connected tothe header editor 212 to receive the edited header. The video merger 214merges the received identification header with the inspection video inconnection with the inspected conduit and sends the resulting video tothe interface unit 216 that conveys it to the video server 50 via thefield relay 16. When the database 198 is updated with new informationabout the inspected underground conduit, the header editor 112 providesthe possibility to automatically update the associated identificationheader as well as the associated inspection video to take into accountthe new information. An update operation in connection with a givenidentification header can be repeated as many times as necessary withoutany risk of deteriorating the quality of the inspection video.

The light projectors of the imaging system are preferably electronicallycontrollable light projectors, such that the operator can control theirintensities remotely. The system provides a camera with a highmagnification zoom surrounded by at least 5 projectors to providenecessary lighting in the inspecting conduit. The reason to place thelight projectors all over the circumference surrounding the camera is tobe able to provide uniform lighting for all the circumference of theconduit without creating shadow zones in the bottom side of the camera.The light projectors should have an appropriate size such that thecircumference on which they stand does not exceed 8 inches to be able toinsert the imaging system in narrow places. The camera and the lightprojectors are preferably contained inside a hexagonal housing with acommon faceplate for both the camera and the light projectors. Thehousing preferably comprises cooling fins and at least onethermoelectric cooling device (ex. Peltier device) to dissipate heatgenerated by the light projectors. The camera and the light projectorsare arranged in such a way that the camera is centered inside thehousing and the light projectors surround the camera.

Moreover, the housing comprises apertures of standard dimensions thatcan receive standard 58 millimeter lens filters and inside of which thelight projectors are located, such that light projected by the lightprojectors is filtered by effect of the standard lens filters in orderto improve quality of imaging. The filters are generally chosen as afunction of the imaging environment. When the latter is a wall of anunderground conduit, the optical filters are generally chosen as afunction of material of the wall and the humidity rate inside theunderground conduit, such that the acquired image shows clearly defectson the wall. When the inspecting conduit is filled with liquid,selection of the optical filters is carried out in consideringreflection characteristics of the liquid, such that the acquired imageis free of light projected by the liquid.

Referring to FIG. 8, there is shown a method of inspecting a conduitusing optical filters. First, the operator determines an appropriatechromatic composition of light to project as a function of imagingenvironment 220. Second, the operator selects appropriate opticalfilters as a function of the appropriate chromatic composition of lightto project 222. Third, the operator poses the selected optical filtersin front of light projectors of the inspection system, such that lightprojected by the light projectors on the inspection object is filteredby effect of the posed optical filters 224. Fifth, the system acquiresthe image of said inspection object 226. Finally, said acquired image isbeing analyzed as a function of the chromatic composition of theprojected light 228.

1. An inspection system comprising: a mast; a support member to supportsaid mast; a camera with a first interface unit to control attributes ofsaid camera, said camera being mounted on said mast; a controllable highmagnification ratio zoom with a zoom controller to control said highmagnification ratio zoom, said zoom being mounted on said mast;electronically controllable light projectors with a second interfaceunit to control attributes of said light projectors, said lightprojectors being mounted on said mast; motors with a motor controller tomechanically control orientation of said camera, said zoom and saidlight projectors with respect to said mast; and a third interface unitlocated in proximity of said camera, said light projectors and saidmotors, said third interface unit having a single input signal andoutput signals connecting said third interface unit to each of saidcamera, said zoom controller, said light projectors and said motorcontroller.
 2. An inspection system as claimed in claim 1, furthercomprising a power supply converter located in proximity of said lightprojectors, said power supply converter receiving a 48 volts current viaa 48 volts cable connected to a remote power supply unit and convertingsaid 48 volts to a 12 volts current in order to supply said lightprojectors.
 3. An inspection system comprising: a mast; a support memberto support said mast; a camera having an output video signal, saidcamera being mounted on said mast; a server connected to said camera tostore at least a part of said video signal outputted by said camera; anda workstation connected to said server to control said video server torecord said video signal and to transmit said recorded video signal tosaid workstation.
 4. An inspection system as claimed in claim 3, whereinsaid camera is an analog camera having a controllable zoom, controllableorientation and controllable lighting for illuminating and imaging saidconduit, said output video signal is an output analog video signal andsaid server is part of a field relay unit providing power to saidcamera, said lighting and positioning motors, said field relay unitbeing connected to said camera to provide control signals and receivesaid output analog video signal from said camera and to said workstationvia a data bus, said server further comprising: a CODEC device receivingsaid output analog video signal and converting said output analog videosignal into a digital video signal and compressing said digital videosignal for storage; and a monitor image generator for sending a livemonitor image from said camera to said workstation over said data bus.5. An inspection system as claimed in claim 3, further comprising motorsmounted on said mast to mechanically control orientation of said camerawith respect to said mast.
 6. A method of automatically generatingattribute values defining controllable attribute values of an inspectionimaging system, said method comprising steps of: manually setting eachof said attribute values to put the inspection system in an initialstate; selecting a navigation template among stored navigationtemplates, where said navigation template contains at least one set ofsaid attribute values defining controllable attribute values of aninspection imaging system; executing said navigation template duringinspection of said inspecting object to generate said at least one setof said attribute values, said attribute values including cameraorientation, camera zoom and lighting intensity; and sending said atleast one set of said attribute values to said inspection imaging systemto automatically navigate according to said selected navigationtemplate.
 7. A method as claimed in claim 6, wherein said at least oneset of said attribute values comprises a sequence in time of a group ofsets of said attribute values.
 8. A method as claimed in claim 6,wherein: said navigation template represent a marked state ofattributes, and sending said at least one set of attribute valuescomprises sending one set of attribute values defined by said markedstate.
 9. A method as claimed in claim 6, wherein said step of selectinga navigation template comprises selecting said navigation template as afunction of a type of said inspecting object.
 10. A system forautomatically generating attribute values defining controllableattribute values of an inspection imaging system, said systemcomprising: a user interface unit receiving user friendly data commandsfrom an end user to define said controllable attribute values; a motorcontrol module connected to said user interface unit to acquire a firstuser friendly data command and outputting a first attribute signal tocontrol position and orientation of said inspection imaging system; azoom module connected to said user interface unit to acquire a seconduser friendly data command and outputting a second attribute signal tocontrol a high magnification ratio zoom of a camera of said inspectionimaging system; a camera module connected to said user interface unit toacquire a third user friendly data command and outputting a thirdattribute signal to control attributes of said camera; a light projectormodule connected to said user interface unit to acquire a fourth userfriendly data command and outputting a fourth attribute signal tocontrol attributes of electronically controllable light projectors ofsaid inspection imaging system; and an interface unit receiving saidattribute signals and outputting corresponding imaging system controlsignals; a storage unit storing navigation templates, where each of saidnavigation templates contains at least one set of said attribute valuesdefining said controllable attribute values of said inspection imagingsystem; a select module connected to said storage unit to select anavigation template among said navigation templates in said storageunit; and an execute module connected to said select module to executesaid desired navigation template and to output said desired navigationtemplate to said imaging system via said interface unit.;
 11. A systemas claimed in claim 10, further comprising: a state save moduleconnected to said storage unit for storing, as a navigation template,said attribute signals corresponding to a current state.
 12. A method ofcreating an identification header using a database to automaticallyextract information in connection with an inspecting object, the methodcomprising steps of: navigating an inspection imaging system mounted ona mast supported by a support member to inspect said inspecting object;recording said inspection to create an inspection video in connectionwith said inspecting object; selecting said inspecting object in adatabase containing information about said inspecting object;extracting, from said database, said information about said inspectingobject; using said extracted information for automatically editing atext identification header in connection with said inspecting object;and merging said text identification header with said inspection videoin connection with said inspection object.
 13. A system for creating anidentification header using a database to automatically extractinformation in connection with an inspecting object, the systemcomprising: An inspection imaging system mounted on a mast supported bya support member to inspect said inspecting object; a storage unitcontaining information about a given group of inspecting objects; aselect module connected to said storage unit to select said inspectingobject among said given group of inspecting objects in said storageunit; a header edit module connected to said select module to edit anidentification header in connection with said inspecting object; and avideo merge module connected to said header edit module to merge saidedited identification header with an inspection video in connection withsaid inspecting object.
 14. An inspection imaging system mounted on amast supported by a support member, said imaging system comprising: acamera with an electronically controllable high magnification ratio zoomto perform inspections both from close up and from a distance; at leastfive light projectors to provide necessary lighting in said undergroundconduit; and a housing containing said camera and said light projectors,said camera being centered in said housing and said light projectorssurrounding said camera.
 15. An imaging system as claimed in claim 14,wherein said housing has a common faceplate for both said camera andsaid light projectors.
 16. An imaging system as claimed in claim 15,wherein said housing has a hexagonal shape.
 17. An imaging system asclaimed in claim 16, wherein said housing comprises cooling fins and atleast one thermoelectric cooling device to dissipate heat generated bysaid light projectors.
 18. An imaging system as claimed in claim 17,further comprising a mast to support components of said imaging systemand motors to mechanically control orientation of said imaging systemwith respect to said mast.
 19. An imaging system as claimed in claim 15,wherein said housing comprises apertures of standard dimensions that canreceive standard 58 millimeter lens filters and inside of which saidlight projectors are located, such that light projected by said lightprojectors is filtered by effect of said standard lens filters.
 20. Amethod of inspecting an inspection object using optical filters, themethod comprising steps of: determining appropriate optical compositionof light to project as a function of an imaging environment; selectingappropriate optical filters as a function of said appropriate opticalcomposition of light to project; placing said selected optical filtersin front of light projectors of said inspection system, such that lightprojected by said light projectors on said inspection object is filteredby effect of said placed optical filters; acquiring an image of saidinspection object; and analyzing said acquired image as a function ofsaid optical composition of said projected light.
 21. A method asclaimed in claim 20, wherein said imaging environment is a wall of anunderground conduit and said selection of appropriate optical filters iscarried out as a function of at least one of humidity inside saidunderground conduit and material of said wall such that said acquiredimage shows defects of said wall.
 22. A method as claimed in claim 20,wherein said imaging environment is an underground conduit filled withliquid and said selection of appropriate optical filters is carried outas a function of at least one of humidity inside said undergroundconduit and reflection properties of said liquid such that said acquiredimage is free of light projected by said liquid.